U.S. patent application number 15/751780 was filed with the patent office on 2018-08-09 for method and apparatus for mitigating bio fouling in reverse osmosis membranes.
The applicant listed for this patent is Aquatech International, LLC. Invention is credited to Ravi CHIDAMBARAN.
Application Number | 20180221827 15/751780 |
Document ID | / |
Family ID | 57984432 |
Filed Date | 2018-08-09 |
United States Patent
Application |
20180221827 |
Kind Code |
A1 |
CHIDAMBARAN; Ravi |
August 9, 2018 |
METHOD AND APPARATUS FOR MITIGATING BIO FOULING IN REVERSE OSMOSIS
MEMBRANES
Abstract
A method and apparatus for reduction of biofouling on reverse
osmosis membranes is provided. One embodiment provides a charged
filter surrounding a cathode that is, in turn, surrounded by an
anode. A plurality of these charged filters may be included in a
larger filtration system that may be included in a typical reverse
osmosis system.
Inventors: |
CHIDAMBARAN; Ravi;
(Canonsburg, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aquatech International, LLC |
Canonsburg |
PA |
US |
|
|
Family ID: |
57984432 |
Appl. No.: |
15/751780 |
Filed: |
August 10, 2016 |
PCT Filed: |
August 10, 2016 |
PCT NO: |
PCT/US2016/046343 |
371 Date: |
February 9, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62203317 |
Aug 10, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C02F 2101/30 20130101;
C02F 2303/04 20130101; B01D 61/04 20130101; C02F 1/441 20130101;
B01D 61/145 20130101; B01D 2311/2626 20130101; C02F 2303/16
20130101; C02F 2103/08 20130101; C02F 2303/20 20130101; B01D
2311/2603 20130101; B01D 2311/04 20130101; B01D 2313/345 20130101;
B01D 65/08 20130101; B01D 61/58 20130101; C02F 1/444 20130101; B01D
2311/2649 20130101; C02F 1/469 20130101; B01D 61/025 20130101; B01D
2311/04 20130101; B01D 2311/2603 20130101; B01D 2311/2649
20130101 |
International
Class: |
B01D 65/08 20060101
B01D065/08; B01D 61/02 20060101 B01D061/02; B01D 61/14 20060101
B01D061/14; B01D 61/04 20060101 B01D061/04; B01D 61/58 20060101
B01D061/58; C02F 1/44 20060101 C02F001/44; C02F 1/469 20060101
C02F001/469 |
Claims
1. A filter system, comprising: a housing having an interior and an
exterior, a filter cartridge on the interior of the housing, said
filter cartridge comprising a cylindrical filter material, said
filter material surrounding a cathode, and said filter material
surrounded by an anode plate; wherein the housing comprises an
inlet, an outlet, a drain, and a vent.
2. The filter system of claim 1, wherein the filter system includes
multiple filter cartridges depending on the design flow.
3. The filter system of claim 1, wherein the filter cartridge is at
least 30'' in length.
4. The filter system of claim 1, wherein the filter cartridge is
between 30''-40'' in length.
5. The filter system of claim 1, wherein the filter cartridge
handles a wide range of flow rates up to 1000 m.sup.3/hour
6. The filter system of claim 1, wherein the cathode is a
cylindrical rod.
7. The filter system of claim 1, wherein the filter material is
positively charged.
8. The filter system of claim 1, wherein the filter material is
negatively charged.
9. The filter system of claim 1, further comprising a power supply
in a circuit with the cathode and the anode.
10. The filter system of claim 9, wherein the power supply is
mounted on the housing.
11. The filter system of claim 1, wherein the housing is
constructed of a material selected from the group consisting of
fiber reinforced plastic, rubber-lined carbon steel, and stainless
steel.
12. A filter system, comprising: a housing having an interior and
an exterior, a plurality of filter cartridges on the interior of
the housing, each of said filter cartridges comprising a
cylindrical filter material, said filter material surrounding a
cathode, and said filter material surrounded by an anode plate;
wherein the housing comprises an inlet, an outlet, a drain, and a
vent.
13. The filter system of claim 12, wherein the filter system has a
water flow rate capacity, and wherein the water flow rate capacity
increases proportionately to the number of filter cartridges in the
filter system.
14. The filter system of claim 12, wherein the filter cartridges
operate in parallel.
15. A method for reducing biofouling on a reverse osmosis membrane,
comprising: treating water comprising biofoulants with an
ultrafiltration membrane; and after treating the water with an
ultrafiltration membrane, treating the water with a charged filter
system.
16. The method of claim 15, wherein said charged filter system
comprises: a housing having an interior and an exterior, at least
one filter cartridge on the interior of the housing, said filter
cartridge comprising a cylindrical filter material, said filter
material surrounding a cathode, and said filter material surrounded
by an anode plate, wherein the housing comprises an inlet, an
outlet, a drain, and a vent; and a power supply in communication
with the cathode and the anode.
17. The method of claim 15, wherein the water comprises an amount
of polysaccharides, and wherein after treatment with the charged
filter system the amount of polysaccharides is reduced.
18. The method of claim 15, wherein the water comprises an amount
of bacteria, and wherein after treatment with the charged filter
system the amount of bacteria is reduced without using any
oxidants.
19. The method of claim 15, wherein there is no difference in
oxidation reduction potential (ORP) value of water across the
filter system.
20. The method of claim 15, further comprising regenerating at
least one filter in the charged filter system in-situ by changing
polarity of the charge and draining previously adsorbed material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
App. No. 62/203,317, filed on Aug. 10, 2015. That application is
incorporated by reference herein.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] Embodiments relate to methods and apparatus for reduction of
fouling on reverse osmosis membranes.
Background of the Related Art
[0003] Bio fouling remains one of the main reasons for fouling on
reverse osmosis membrane during treatment of sea water or waste
water. Many pretreatment and disinfection methods have been tried
but they have not been effective in mitigating this problem. Many
approaches, like chlorination and de-chlorination, have on the
contrary made the problem worse. This is because the presence of
residual bacteria and highly oxidized organic products that are
present after the oxidation still increase the bio fouling
potential of the water.
[0004] Ultrafiltration provides 6 log reduction of bacteria and
partially removes some organic matter, but the residual organics
and bacteria still result in serious bio fouling. In particular,
transparent exopolymer particles ("TEPS") are known to pass the
ultrafiltration membrane and cause primary fouling. This, in turn,
causes subsequent secondary fouling due to the residual bacteria.
This results in irreversible flux loss through the membranes and
slowly increases the differential pressure (DP) in spite of
frequent cleaning.
BRIEF DESCRIPTION OF THE INVENTION
[0005] It would be beneficial to mitigate bio fouling in the RO
membranes, which happens in the seawater and waste water based
desalination plants. Embodiments as reported herein address a root
cause of bio fouling by treating both organics and the bacteria
that are responsible for bio fouling. The invention is based on an
electro chemical method accomplished through a filtration and
electrode assembly device.
[0006] The filtration device works on a surface charge mechanism by
adsorbing charged particles like TEPs downstream of the UF, which
are carried through UF in the permeate. The electrode device
includes a cathode and an anode and de-activates the bacteria under
the influence of a mild DC current. This keeps the surface of the
filter clean by regenerating it and removing the adsorbed organics
and allowing it to drain. During regeneration the polarity of the
electrodes is reversed. This provides ideal conditions for
regeneration because the conditions are like almost clean
conditions. This also increases the life of the filter by
preventing increase in the filter DP. Mechanically the filter and
the electrodes are encapsulated in a plastic or a metal housing.
The filter elements can be pulled out for replacement.
[0007] Embodiments may provide a filter system including a housing
having an interior and an exterior, a filter cartridge on the
interior of the housing, said filter cartridge comprising a
cylindrical filter material, said filter material surrounding a
cathode, and said filter material surrounded by an anode plate;
wherein the housing comprises an inlet, an outlet, a drain, and a
vent. In certain embodiments the filter system includes multiple
filter cartridges on the interior of the housing.
[0008] In further embodiments the filter system includes multiple
filter cartridges depending on the design flow. In further
embodiments the filter cartridge is at least 30'' in length. In
some embodiments the filter cartridge is between 30''-40'' in
length.
[0009] In some embodiments there are more than one filter
cartridge, and they operate in parallel. Embodiments may handle a
wide range of flow rates. For example, they may handle flow rates
of up to 1000 m.sup.3/hour.
[0010] In some embodiments the cathode is a cylindrical rod. In
some embodiments the filter is positively charged filtration media.
In other embodiments it is negatively charged filtration media.
Embodiments may include a power supply in a circuit with the
cathode and the anode. That power supply may be mounted directly on
the filtration system housing. The housing may be constructed, for
example, of a material selected from the group consisting of fiber
reinforced plastic, rubber-lined carbon steel, and stainless
steel.
[0011] In embodiments the filter system has a water flow rate
capacity, and wherein the water flow rate capacity increases
proportionately to the number of filter cartridges in the filter
system.
[0012] Embodiments may further provide methods for reducing
biofouling on a reverse osmosis membrane, including treating water
comprising biofoulants with an ultrafiltration membrane; and after
treating the water with an ultrafiltration membrane, treating the
water with a charged filter system. In such embodiments the charged
filter system may include a housing having an interior and an
exterior, at least one filter cartridge on the interior of the
housing, said filter cartridge comprising a cylindrical filter
material, said filter material surrounding a cathode, and said
filter material surrounded by an anode plate, wherein the housing
comprises an inlet, an outlet, a drain, and a vent; and a power
supply in communication with the cathode and the anode.
[0013] In some embodiments the water to be purified includes an
amount of polysaccharides, and wherein after treatment with the
charged filter system the amount of polysaccharides is reduced. In
further embodiments the water to be purified includes an amount of
bacteria, and wherein after treatment with the charged filter
system the amount of bacteria is reduced without using any
oxidants. In some embodiments there is no difference in oxidation
reduction potential (ORP) value of water across the filter
system.
[0014] Further embodiments include regenerating at least one filter
in the charged filter system in-situ by changing polarity of the
charge and draining previously adsorbed material.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 shows an electro-biofoulant removal filter as
reported herein in embodiments of the invention.
[0016] FIG. 2 shows a top view of a multi-filter assembly of an
electro-biofoulant removal filter for high flows.
[0017] FIG. 3 shows flow diagrams of electro-biofoulant removal
filters in operation.
[0018] FIG. 4 shows an FTIR curve of a filter's deposited material
showing --OH (hydroxyl) and --COOH (carboxyl) peaks indicating the
presence of TEP in the tested material.
[0019] FIG. 5 shows an Alcian Blue test for polysaccharides in an
electro-biofoulant removal filter of an embodiment as reported
herein.
DETAILED DESCRIPTION OF THE INVENTION
[0020] I. Methods for Reducing Bio Fouling
[0021] Embodiments provide a process and equipment solution for bio
fouling problem which is experienced in surface water and waste
water based reverse osmosis plants. Typically this bio fouling
results from the inability of the pretreatment process to
adequately address this problem. Certain organics, which possess
bio-fouling potential even pass through ultrafiltration membranes
that provide 6-7 log bacteria reduction. But because of the
carryover of both bacteria and organics (which may provide a food
source for the bacteria), bio fouling takes place in the RO
membrane.
[0022] RO membranes reject both bacteria and organics. The fouling
primarily starts due to organics on the membrane surface. These
organics become feed for bacteria and result in their exponential
growth of bacteria. This initiates complex fouling. This further
results in tertiary fouling due to the precipitation of inorganics
like silica, heavy metals, hardness etc. This form of fouling
results in significant pressure drop, does not respond to chemical
cleaning, and becomes irreversible over a period of time.
Eventually the membranes have to be replaced.
[0023] In sea water reverse osmosis plants, in spite of having UF
pretreatment, contaminants like TEPs (Transparent Exo-polymer
substances) pass through UF membranes. Combined with the presence
of bacteria, these TEPs cause bio fouling on the RO membranes, as
described above, and result in frequent membrane cleaning and
eventual replacement. When the system is operated with continuously
increasing differential pressure there is an increasing trend in
energy consumption and operational costs.
[0024] Embodiments provide a solution to minimize or eliminate the
bio fouling caused by naturally occurring organics and bacteria.
The filter is made of a blend of organic and inert inorganic
material, which includes a charge. The charge is caused by
incorporating a anionic or cationic functional group into the
filter, either by a chemical reaction or by incorporating ion
exchange resin materials. The filter, with its charged surface,
adsorbs organics. The filter works in presence of electrodes under
the influence of DC electric current. The electrical field helps in
keeping the adsorbtion bonding between the filter and the organics
if any, labile and loose during the service cycle.
[0025] During the service cycle the DC voltage has a positive
charge around the filter and a negative charge inside the filter.
The polarity is reversed for regeneration for few seconds, when the
electrode outside the filter becomes negative and inside the filter
becomes positive. At this time the voltage is also increased to
increase the current, and the drain is opened which cleans the
filter and reduces the dP across the filter. Due to this the life
of the filter is extended and the differential pressure remains
less than 15 PSI and most between 5-10 psi.
[0026] As the water is coming out of ultrafiltration pretreatment,
most of the suspended solids and colloidal material is filtered by
ultrafiltration membrane. Therefore the downstream filter does not
need to remove any suspended or colloidal particles. If the
ultrafiltration membrane is not present upstream, most of the
suspended and colloidal particles will be removed by the down
stream filter and it will be quickly be used and the differential
pressure will mount quickly. Also its surface charge will be fully
blocked by the debris and the same will not be effective to remove
any organics in water.
[0027] This filter also deactivates bacteria by damaging and
rupturing the walls of its cells. The breeding of bacteria is
stopped without using any external oxidants, which also create
potent food for the bacteria that may survive the oxidation
process. In this case there is no production of oxidizing material,
as evidenced by the fact that ORP values measured at the inlet and
outlet remain the same and by the fact that there is no increase of
ORP across the filter.
[0028] We have further noted that if the filter operates without
any voltage the increase of dp is very rapid, and we can see bio
fouling on the filter itself as it turns blackish brown within few
days of operation and starts smelling bad. Whereas under the
influence of the electric voltage the bio-fouling of filter is
stopped, the filter removes bio foulants very efficiently. This
filter can be regenerated in place just by changing the polarity to
get a longer life of few months and prevents any down stream bio
fouling of the reverse osmosis membranes.
[0029] After several days of service in sea water down stream of an
ultrafiltration system the filter units may be removed for
replacement. A brown deposit or coating is seen on the filter
surface. Such coating was predominantly seen where the regeneration
was not possible because of lack of access. The brown deposits were
scraped off and taken for FTIR analysis. FTIR showed peaks
typically representing --OH (hydroxyl) and --COOH (carboxyl)
groups, which are normally present in TEPs, which are
polysaccharide materials found in sea waters.
[0030] This material was further subject to Alcian blue testing
side by side with a standard xanthan gum. The feed water, which
contained polysaccharides, and the drain water, which contained
most of the removed polysaccharides during regeneration, showed
maximum absorbance of Alcian blue and lower concentration in the
filtered water of these waters through 0.2 micron filter. The
filter paper in this cases got highest concentration of stain. The
treated water showed very little coloration in the water sample and
staining on the filter paper. The colorimetric analysis showed more
than 90% reduction of polysaccharides through the bio foulant
removal filter.
[0031] II. Apparatus for Reducing Bio Fouling
[0032] Filter material useful in embodiments of the invention is
available as flat sheet, spiral wound material or in the form of
cartridges. The filters can be made with anionic material or
cationic material depending on the composition of organic
contaminants in the feed water.
[0033] One of the embodiments of the filter construction has been
detailed in FIG. 1. In this embodiment the filter has been
constructed from positively charged cartridges. The filter is
placed in a housing, which is designed to withstand pressure. The
housing 1 can be designed for any pressure but typically between
100-150 psi design pressure, which works well for filter at the
outlet of ultrafiltration system. The filter typically has an
inlet, outlet, drain and vent nozzles.
[0034] In a single element filter the cartridge element 2 sits at
the center. The filter is fitted and sealed with the help of
O-rings and gaskets such that the feed and filtered water streams
can be kept separate without any mixing. The filter is surrounded
by an anode plate 3, which is made of a perforated material.
Typically this material is 1-6 mm thick, preferably 2-3 mm thick.
The anode material can be stainless steel material, preferably
SS316 grade. Titanium may also be useful, particularly for water
containing high levels of chloride, like seawater. Depending on the
analysis of water and the pH different grades of anode material can
be selected from, for example, different grades of stainless steel,
titanium, tantalum or Hastelloy.RTM. brand alloys.
[0035] The cathode 4 is normally a rod that sits inside the
cartridge. Typically it is a stainless steel material. It is also
possible to make the cathode out of studs that are normally used to
keep the cartridge bolted in place or something that is used to
enclose the housing.
[0036] The electrodes are connected with a Direct Current (DC)
power supply. Typically an ammeter and voltmeter are part of the
circuit to measure voltage and the current. The filter housing has
valves in the inlet, outlet, drain and vent nozzles so that the
valves can be opened and closed during the service and the
regeneration cycles.
[0037] The filters are also designed for handling larger flows and
the design can be scaled up by increasing the number of filters, In
this case the filters operate in parallel. An embodiment of a
filter with multiple elements is shown in FIG. 2. The filter has
been designed to handle around 400 m.sup.3/hour of flow. One can
use multiple of these filters to handle higher flows. For a flow of
1200 m.sup.3/hr, for example, typically there would be four filters
and one of the filters can be taken for regeneration while the rest
of the filters are performing filtration service.
[0038] In a preferred embodiment the filters are 40'' in length. In
a further preferred embodiment one housing will have approximately
one hundred cartridges. Each cartridge will have one anode and a
cathode. The anode will be on the outside surrounding the
cartridge, and the cathode will be inside the cartridge similar to
the arrangement explained above. Similar designs can be created for
filtration units for different flow rates.
[0039] FIG. 2 has housing 1, cartridge elements 2, cathode 4 and
anode 3. In this case all the cathodes and anodes are connected
together to create one pair of external connections with the DC
supply. The DC supply box 5 can be mounted on the filter housing.
Multiple filter units can be mounted on a skid, which can be piped
with inlet, outlet and drain and vent headers combing all the
filters. The filter housings are typically constructed of fiber
reinforced plastic (FRP) material or alternatively rubber lined
carbon steel or stainless steel material.
EXAMPLES
[0040] I. Experiment 1
[0041] In this example, an electro-biofoulant removal filter was
fabricated as shown in FIG. 1. A positively charged cartridge
element 2 of size 2.5.times.40 inch was fitted in PVC housing 1. A
perforated titanium anode plate 3 was assembled around cartridge
element and stainless steel cathode rod 4 is fitted at center of
cartridge element 2.
[0042] The filter was made leak proof and operated at a salt-water
reverse osmosis SWRO plant site for 73 days as shown in FIG. 3. UF
product water was fed into the device filter and operated with DC
current. During service flow, the filter was operated by applying
10 to 20 mA DC current and inlet and outlet water turbidity were
monitored. Daily one regeneration cycle for 1 to 2 minutes was
performed on filter and filter regeneration was done by applying 30
mA current in reverse polarity and during regeneration cycle,
reject water was drained through drain line and drain water
turbidity was also recorded.
[0043] It was observed that during 73 days testing filter
differential pressure (DP) remained constant and differential
pressure regained after regeneration process. Filter operating data
are summarized in Table 1. ORP of inlet and outlet water across
filter were also monitored and observed nearly same values. No
changes in ORP were observed. ORP values are summarized in Table
2.
TABLE-US-00001 TABLE 1 Electro-biofoulant Removal Filter Operating
Data Inlet Outlet Drain Current Current Operating turbidity,
turbidity, turbidity, during during DP before DP after Days NTU NTU
NTU service, mA regen, mA regen, psi regen, psi 1 0.09 0.09 0.21 10
30 11 11 2 0.06 0.05 0.11 10 30 11 11 3 0.07 0.06 0.15 10 30 11 11
4 0.06 0.06 0.09 10 30 14.5 14.5 5 0.09 0.08 0.15 10 30 14.5 14.5 6
0.11 0.08 0.11 10 30 14.5 14.5 7 0.08 0.08 0.09 10 30 14.5 14.5 8
0.12 0.10 0.12 10 30 14.5 14.5 9 0.12 0.08 0.12 10 30 14.5 14.5 10
0.11 0.09 0.14 10 30 14.5 14.5 11 0.14 0.09 0.14 20 30 14.5 14.5 12
0.13 0.10 0.14 20 30 14.5 14.5 13 0.08 0.08 0.12 20 30 14.5 14.5 14
0.09 0.08 0.11 20 30 14.5 14.5 15 0.12 0.1 0.13 20 30 14.5 14.5 16
0.12 0.09 0.12 20 30 14.5 14.5 17 0.1 0.09 0.11 20 30 14.5 14.5 18
0.11 0.09 0.13 20 30 14.5 14.5 19 0.12 0.1 0.12 20 30 14.5 14.5 20
0.12 0.09 0.15 20 30 14.5 14.5 21 0.12 0.1 0.13 20 30 14.5 14.5 22
0.12 0.09 0.13 20 30 14.5 14.5 23 0.12 0.1 0.11 20 30 14.5 14.5 24
0.12 0.1 0.12 20 30 14.5 14.5 25 0.09 0.08 0.1 20 30 14.5 14.5 26
0.1 0.09 0.1 20 30 14.5 14.5 27 0.11 0.1 0.11 20 30 14.5 14.5 28
0.12 0.11 0.12 20 30 14.5 14.5 29 0.13 0.11 0.12 20 30 14.5 14.5 30
0.1 0.09 0.12 20 30 14.5 14.5 31 0.12 0.1 0.13 20 30 14.5 14.5 32
0.09 0.09 0.11 20 30 14.5 14.5 33 0.12 0.1 0.12 20 30 14.5 14.5 34
0.08 0.08 0.1 20 30 14.5 14.5 35 0.11 0.09 0.12 20 30 14.5 14.5 36
0.12 0.11 0.12 20 30 14.5 14.5 37 0.09 0.08 0.11 20 30 14.5 14.5 38
0.09 0.09 0.1 20 30 14.5 14.5 39 0.11 0.11 0.13 20 30 14.5 14.5 40
0.12 0.1 0.12 20 30 14.5 14.5 41 0.13 0.1 0.13 20 30 14.5 14.5 42
0.11 0.1 0.13 20 30 14.5 14.5 43 0.11 0.11 0.12 20 30 14.5 14.5 44
0.13 0.1 0.13 20 30 16 16 45 0.11 0.1 0.11 20 30 16 16 46 0.1 0.1
0.12 20 30 16 16 47 0.08 0.08 0.11 20 30 16 16 48 0.09 0.08 0.11 20
30 16 16 49 0.11 0.1 0.12 20 30 16 16 50 0.1 0.1 0.12 20 30 16 16
51 0.12 0.09 0.14 20 30 22 14.5 52 0.13 0.09 0.15 20 30 22 14.5 53
0.14 0.09 0.16 20 30 22 16 54 0.08 0.05 0.11 20 30 16 16 55 0.13
0.1 0.15 20 30 14.5 13 56 0.12 0.1 0.13 20 30 13 13 57 0.13 0.1
0.15 20 30 13 13 58 0.11 0.08 0.13 20 30 13 13 59 0.1 0.08 0.12 20
30 13 13 60 0.11 0.08 0.13 20 30 20 16 61 0.12 0.09 0.14 20 30 20
14.5 62 0.1 0.09 0.11 20 30 14.5 14.5 63 0.11 0.09 0.12 20 30 14.5
14.5 64 0.11 0.09 0.13 20 30 14.5 14.5 65 0.1 0.09 0.11 20 30 14.5
14.5 66 0.12 0.09 0.13 20 30 14.5 14.5 67 0.11 0.08 0.12 20 30 14.5
14.5 68 0.12 0.09 0.13 20 30 14.5 14.5 69 0.11 0.08 0.14 20 30 16
16 70 0.11 0.09 0.13 20 30 16 14.5 71 0.12 0.1 0.13 20 30 16 14.5
72 0.12 0.1 0.12 20 30 14.5 14.5 73 0.11 0.09 0.12 20 30 14.5
14.5
TABLE-US-00002 TABLE 2 ORP values across filter Operating Inlet
water Outlet Water Days ORP, mV ORP, mV 62 251 250 65 200 190 69
221 207 72 226 225 73 239 236
[0044] II. Experiment 2
[0045] During operation of Experiment 1, water across filter was
analyzed for microbiological analysis and bacterial count results
are summarized in Table 3. Filter inlet, outlet and drain water was
also checked for TEP (polysaccharides) content by Alcian blue test
method and results shows 90% reduction of TEP in filtered outlet
water (results shown in Table 4 and FIG. 5). FTIR analysis was also
done on brownish deposit or coating on filter surface after
operation of several days and results showed peaks of --OH
(hydroxyl) and --COOH (carboxyl) groups, which are normally present
in TEPs (see FIG. 4). These results indicate that invented device
filter is effectively adsorbing and removing bacteria and TEPs from
water.
TABLE-US-00003 TABLE 3 Microbiological Analysis of water samples
across filter Pilot Filter Pilot Filter Parameters Units Drain
Product Total Bacterial Count CFU/ml 1.8 .times. 10.sup.2
<10.sup.2 Total Coliforms CFU/100 ml 32 NIL Fecal Coliforms
CFU/100 ml -- -- Enterococci CFU/100 ml -- -- Pseud0monas
aeruginosa CFU/250 ml -- -- Total Chlorine mg/L 0 0 Free Chlorine
mg/L 0 0
TABLE-US-00004 TABLE 4 TEPs/polysaccharide content across filter
water samples SAMPLE DESCRIPTION UNIT RESULTS Filter Inlet water
PPM 22.7 Filtered Outlet water PPM 2.1 Filter Drain water PPM 37.7
Polysaccharides Removal % 90.75 Efficiency
* * * * *